Gun, drugs, and motor vehicles are by no means strictly American causes of death, but they affect American far more than in other developed nations, so much so that they account for “a full year — about half of the disadvantage that American men face” in the United States than elsewhere, according to Andrew Fenelon, a researcher with the National Center for Health Statistics, a division of the Centers for Disease Control and Prevention (CDC), and one of three authors of the study.